All of us can understand the concepts of having properly "sized" and maintained brakes, never driving faster than your car can stop, and, drum roll please...always having ample stopping power for a street rod that's standing still. What? Yes, it's just as important that your street rod be able to stay motionless when not moving as it is for it to be able to stop when it is moving.
A play on words and a bit of verbal trickery, possibly, but fact nonetheless. A good parking brake system is as necessary as any other safety component on your street rod but oftentimes goes overlooked. We are going to show you how you can have improved rear braking along with a terrific parking brake while still having a system that is candy to the eye.
We followed along step-by-step as Dean Livermore of Hot Rods by Dean in Phoenix, Arizona, installed a Wilwood (Camarillo, CA) disc/drum internal parking brake kit on a Currie (Anaheim, CA) 9-inch Ford rearend. Wilwood also offers this disc/drum kit for many of the popular rearends that may be found under a street rod, such as for a Ford 9- or 8-inch, 12-bolt Chevy with C-clip, '58-64 Olds or Pontiac, '93-02 Camaro or Firebird, or for some Mopar/Dana among other rearends.
Before going further into detail let's go over what will not be covered. We will not cover the brake lines, fittings, proportioning valve, residual check valves, master cylinder, brake pedal, or the emergency brake cable hookup. In an upcoming issue of STREET RODDER we will provide proper coverage of these equally important items. However, what we will cover in this story is the procedure required to install the rear axle disc/drum internal parking brake system.
The rear disc/drum internal parking brake kit can be ordered with one-piece solid 0.50-inch thick rotors or with one-piece vented 0.81-inch thick rotors. The rotors have a diameter of 12.19 inches. While offering substantial braking surface they also guarantee a presence ample enough to fill the oversized "windows" in today's billet wheels. The rotors come in either a standard or drilled/slotted configuration with a dual-lug pattern (5 on 4 1/2 and 5 on 4 3/4), which addresses the popular Ford, Mopar, and Chevy wheel bolt patterns. The drilled and slotted rotors are silver zinc washed to prevent rust from occurring on the areas not in contact with the PolyMatrix brake pads.
A word on the PolyMatrix pads. They are 100 percent asbestos free, are integrally molded and fused to their backing plates, have no rivets or flat adhesive bonds to fail as a result of high heat, and have no punched holes or stamped dimples to further weaken or distort the plates. According to Wilwood, "A patented retention system was developed to provide the strongest, quietest, safest, and most reliable method of securing the friction material to the backing plate." There are different heat range pads for different applications. When ordering a kit you will want to stress that your application is for a street rod. Again, according to Wilwood, the PolyMatrix pads come in various compounds with single letter designations; A, B, C, D, E, J, T, and Q. These designations mean that the pads can handle anything from all-out racing, such as NASCAR, to the demands of a street rod or musclecar. The Q compound description states that its best suited for the demands of street rodding. The pad is based in a ceramic enhanced formula developed for ultra quiet performance with excellent stopping and low dust characteristics. Just what the brake doctor ordered for highly polished wheels. The disc/drum parking brake kits come with a PolyMatrix T-compound pad (PN 7112T) that can be switched out at the time of ordering. Or, you can keep the economically priced T-pads; they possess excellent characteristics for a break-in pad for bedding new iron rotors and offer immediate cold response. The T-pads and backing plate for our kit (PN 140-7140PD) (polished calipers and drilled rotors) measure 3.96 inches wide, 2.38 inches tall, and .49 inch thick.
The crown jewels of this impressive brake package are the pair of forged billet Dynalite calipers (each fitted with four 1.38-inch stainless steel pistons and PolyMatrix pads) that can be ordered in a polished or anodized black finish. The calipers are fitted with four-corner bleed screws and feature the SRS stainless steel bridge plates, which reduce the noise normally associated with this style of caliper.
It's a mix and match to suit your car's braking needs and aesthetic values. All of the hardware (Grade 8 and aircraft), including caliper alignment shims, is provided along with the proper torque specifications to guide you throughout the assembly process. The billet aluminum CNC-machined mounting brackets are used to hold the calipers and serve as the backing plates.
It should be noted that while OEM parking brake cables may work, you are building a street rod, which will more than likely require a custom fix. To this end Lokar Performance (Knoxville, TN) offers a complete line of cables to ensure that your parking brake system will function properly as well as look good. (Remember, we are going to feature this in an upcoming issue of SRM.) The internal parking brake assembly is a mechanically operated twin shoe system that is "hidden" within the rotor-mounting hat. The drum parking brake is shipped already pre-assembled, which ensures an easier and quicker installation. Shoe adjustment is achieved through the backing plate.
So much for the textbook approach, let us follow along as the installation is performed at Hot Rods by Dean. Remember to stay tuned for subsequent issues of SRM, in which we'll deal with all those "other" items required to make your braking system all that it should be.
The "exploded" view of the...
The "exploded" view of the Wilwood disc/drum internal parking brake kit is a complete and integral rear disc/drum-fitting package that uses the available space wisely.
The mechanically operated...
The mechanically operated drum parking brake comes fully assembled to both quicken the installation and eliminate potential errors.
We started with a Currie 9-inch...
We started with a Currie 9-inch drum brake rearend. Note the Currie axle doesn't have an access hole, which is required to "get" to the nuts that will eventually secure the parking brake in position. A hole must be drilled and this can be done while the axle is in place or removed.
We used our newly drilled...
We used our newly drilled access hole to remove the original drum backing plate hardware. This allowed the rear drum brake assembly to be eliminated.
The basics of the drum parking...
The basics of the drum parking brake segment include the bracket kit (PN 249-7110/11), a pair of U-retainers (PN 250-6286), and a pair of rotors (PN 160-6968/69).
The forged billet Dynalite...
The forged billet Dynalite calipers can be ordered in a polished or anodized black finish. In this application the polished (PN 120-6791-P) calipers are installed.
The rotor/hat assembly can...
The rotor/hat assembly can be ordered plain or drilled/slotted (as pictured). Note the hat section acts as the "home" for the mechanically operated parking brake. The rotors are silver zinc washed to prevent rust from occurring on the areas not in contact with the pads.
The parking brakes come assembled...
The parking brakes come assembled and are easily installed. The assembly bolts directly to the axle-bearing flange.
With the parking brake resting...
With the parking brake resting inside the rotor/hat you can see the parking brake assembly also holds the caliper bracket as well.
The full circle bearing retainer...
The full circle bearing retainer on the axle is stock and if you wish to use this style then a machine shop will be needed to press off the bearing to remove the stock retainer. (Now would be a good time to install a new bearing, not supplied with kit.) Note that the Wilwood U-retainers should be installed with lip facing toward bearing.
There is another way to remove...
There is another way to remove the full circle bearing retainer other than by the pressing off of the wheel bearing. You can cut or grind a notch that will allow the retainer to "pass" over the axle. Pictured is a Wilwood U-retainer that can be installed without removal of the bearing. But, note that the lip faces toward the bearing and that the "U" opening should be facing up once installed.
The parking brake assembly...
The parking brake assembly bolts directly to the axle-bearing flange but you cannot tighten it down yet, that's why the axle needs the access hole. You will see why shortly.
You can now slide the axle...
You can now slide the axle in as well as place the U-retainer in position. Once you tighten the retainer the axle and parking brake assembly are secured.
The access hole comes in handy...
The access hole comes in handy for tightening down the mounting bolt/nut, which holds the U-retainer and parking brake assembly in place.
Part of the Wilwood parking...
Part of the Wilwood parking brake assembly is this handy bracket, which holds the cable assembly. Street rods are custom in their assembly and you will most likely need Lokar Performance parking brake cables.
The rotor/hat assembly comes...
The rotor/hat assembly comes with a dual bolt pattern to accept Chevy (5 on 4 3/4) or Ford (5 on 4 1/2) spacing.
To ensure caliper alignment...
To ensure caliper alignment over the rotor, 12 shims (each 0.032-inch) are provided. Place these shims between the caliper and the bracket. Wilwood recommends using red Loctite 271 applied to the mounting bolt threads, then torque to 30 ft-lb. Next, it's recommended that you safety wire the caliper mounting bolts.
(This is a specialty item...
(This is a specialty item requiring certain tools and talent, if you don't have it, seek a qualified individual.)
Viewed from the bottom, the...
Viewed from the bottom, the PolyMatrix pads are in position. According to Wilwood, "A patented retention system was developed to provide the strongest, quietest, safest, and most reliable method of securing the friction material to the backing plate."
The Wilwood rear disc/drum...
The Wilwood rear disc/drum internal parking brake is impressive and yields enhanced stopping power whether you are moving or not! (Okay, before anyone writes in--yes, that's a rubber band holding the cotter pin in place. The pin is yet to be bent--a little trick to hold the pin in place without actually "using" it.)
Note that the rear caliper...
Note that the rear caliper bracket bolts directly to the parking brake assembly. The calipers are fitted with four-corner bleed screws, meaning that the calipers can be used on either the right or the left side of the vehicle.